The AgrImpact project provides an innovative approach to impact evaluations by both assessing the current effectiveness of promoting agroecological practices through farmer field schools (FFS) and modelling their future effectiveness as an adaptation strategy to climate change in Madagascar. Madagascar’s southern regions are characterised not only by high food insecurity, its agricultural sector is also highly vulnerable to a changing climate. Agroecological practices, such as agroforestry, soil cover and crop diversification, are said to improve farmers’ resilience in the face of climate change, and are an integral part of German development cooperation in the agricultural sector. FFS, a method of experiential adult agricultural education, are an established methodology in agricultural extension, but understudied when it comes to more systemic approaches such as agroecology. Using an integrated design, we will first conduct a randomised controlled trial (RCT) to measure the short-term effects of FFS promoting agroecological practices on productivity, food security and nutrition, income and labour use, as well as farmers’ mental models. As far as possible, we will include an assessment of heterogeneous impacts on different vulnerable groups, including women. Then, we will use climate impact models to project the effectiveness of these agroecological practices under different climate change scenarios, integrating empirical data collected during the RCT. Given expectations of a changing climate, this approach allows us to create a scientific basis for both current and future development policy decisions as today's practices will not necessarily be suitable and efficient to solve challenges in future climates. Finally, the proposed project can build on a long-standing, strategic collaboration between PIK and the GIZ, as well as the BMZ, with the aim of evidence-based decision support.